From 3c43f7c0e6bd0013181f51abf25b1cae33b93def Mon Sep 17 00:00:00 2001
From: Himani Negi <negi.himani11@gmail.com>
Date: Fri, 27 Dec 2019 16:57:24 +0530
Subject: [PATCH] Add backtracking/nqueen_print_all_solutions.cpp (#622)

* Add files via upload

* Rename Backtracking/NQueen-PrintAllSolutions.cpp to backtracking/nqueen_print_all_solutions.cpp

* clang-format -i -style="{IndentWidth: 4}" *.cpp

* endl --> std::endl

Co-authored-by: Christian Clauss <cclauss@me.com>
---
 backtracking/nqueen_print_all_solutions.cpp | 50 +++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 backtracking/nqueen_print_all_solutions.cpp

diff --git a/backtracking/nqueen_print_all_solutions.cpp b/backtracking/nqueen_print_all_solutions.cpp
new file mode 100644
index 000000000..e6736da1e
--- /dev/null
+++ b/backtracking/nqueen_print_all_solutions.cpp
@@ -0,0 +1,50 @@
+#include <iostream>
+#define n 4
+
+void PrintSol(int Board[n][n]) {
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < n; j++) {
+            std::cout << Board[i][j] << " ";
+        }
+        std::cout << std::endl;
+    }
+    std::cout << std::endl;
+}
+
+bool CanIMove(int Board[n][n], int row, int col) {
+    /// check in the row
+    for (int i = 0; i < col; i++) {
+        if (Board[row][i] == 1)
+            return false;
+    }
+    /// check the first diagonal
+    for (int i = row, j = col; i >= 0 && j >= 0; i--, j--) {
+        if (Board[i][j] == 1)
+            return false;
+    }
+    /// check the second diagonal
+    for (int i = row, j = col; i <= n - 1 && j >= 0; i++, j--) {
+        if (Board[i][j] == 1)
+            return false;
+    }
+    return true;
+}
+
+void NQueenSol(int Board[n][n], int col) {
+    if (col >= n) {
+        PrintSol(Board);
+        return;
+    }
+    for (int i = 0; i < n; i++) {
+        if (CanIMove(Board, i, col)) {
+            Board[i][col] = 1;
+            NQueenSol(Board, col + 1);
+            Board[i][col] = 0;
+        }
+    }
+}
+
+int main() {
+    int Board[n][n] = {0};
+    NQueenSol(Board, 0);
+}